David Barry and his fiancée, Samantha Burns. The couple will be married on Friday and then march in the St. Patrick’s Parade on Saturday.

When the Rockville Centre St. Patrick’s Parade steps off on Saturday, there will be a special group marching in it. In addition to the pipe bands, firefighters, police officers and Irish cultural societies, there will also be a wedding party.

David Barry and his fiancée, Samantha Burns, planned their wedding, which is set for Friday afternoon, to coincide with the parade, which has been a tradition in Barry’s family for years. “We have a family tradition called the Barry Bash,” Barry said. “Originally it was just our immediate family. Then we had a couple of friends over. After years, it’s about 150 people now that come to this house party before the parade.”

The Barrys, who are from Ireland — David was born there — turn Irish Day into a big celebration every year. But because of the wedding, many relatives from Ireland will be in town and will be marching in the parade — although they don’t know it yet.

“We’re picking them up on Wednesday night, they’re staying at the Hampton Inn in Rockville Centre, and our wedding is on Friday night,” Barry said. “The next morning, they have no idea they’ll be walking in the parade.”

The wedding has been a long time in the making. Barry contacted the parade committee three years ago to find out when the 2014 parade would be.

The couple, who now live in East Rockaway, have been together for eight years. Their relationship began in Rockville Centre, so it made sense to both of them to get married here. “[Samantha] loved the idea because she knew how much the day means to me and my family,” Barry said. “I met her at Stingers in Rockville Centre, and we got engaged at Monahan’s.”

The couple is even including the bar in their wedding: after the ceremony, at St. Agnes Cathedral, a group of bagpipers will lead the newlyweds and their guests to Monahan’s, where the couple will buy everyone a drink before they all board buses and head to the reception at the North Ritz Club in Syosset.

The next day, Barry, his new wife and about 30 of his family members (20 or so from Ireland) will march in the parade.

“It’s almost my dream day,” David said. “It’ll be the first time my family and friends are in a room together in my life. It’ll be the first time half my family is in the United States.

“There was no other day when we were looking into it,” he added of the wedding. “We planned it for this day.”

The only problem he has encountered so far is his mother. “The funny thing is, my mother wanted to leave the wedding early to cook sausages for the morning,” he said. “And this was a big argument. I think this year they might have [the Barry Bash] catered. “But I bet you anything my parents leave my wedding to cook sausages.”